\relax 
\@writefile{toc}{\contentsline {subsection}{\numberline {3.1}Relativistic Kinematics}{19}}
\@writefile{toc}{\contentsline {subsection}{\numberline {3.2}Photons and Planck's Hypothesis}{20}}
\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces }}{21}}
\@writefile{toc}{\contentsline {subsection}{\numberline {3.3}Two examples of kinematic calculations}{22}}
\@writefile{toc}{\contentsline {subsubsection}{\numberline {3.3.1}Example I: Threshold Energies}{22}}
\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces The upper figure shows how the collision appears in the laboratory frame. The lower figure shows the collision in the centre-of-momentum frame.}}{24}}
\@writefile{toc}{\contentsline {subsubsection}{\numberline {3.3.2}Example II: Elastic collisions}{24}}
\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces }}{25}}
\@writefile{toc}{\contentsline {subsection}{\numberline {3.4}The three-force and four-force}{26}}